In conventional construction vehicles such as wheel loaders, it is common practice to place the same size tire on both the front and the rear of the vehicle. While this has been known to work quite well in most instances, the tire size that is chosen for each individual vehicle is normally dictated by the functional requirements of the front tires. Since the 0 majority of the operational loads are carried by the front end of the vehicle, the functional requirements for the rear tires are not the same as those on the front. However, in order to maintain commonality of tire size between the front and rear of the vehicle the rear tires are usually much larger that would be required by normal working conditions. This situation results in an unnecessary increase in the height of the rear portion of the vehicle which in turn, increases the center of gravity of the vehicle and tends to hamper serviceability. The larger rear tire also tends to increase the wheelbase of the vehicle thus creating a larger turning radius.
In other instances, such as agricultural equipment, a set of wheels on one end of a vehicle may be of a different size with respect to the set of wheel on the other end of the vehicle. In these instances however, the driveline, which includes a pair of drive shafts, is "stepped" through the use of a drop box to lower the elevation of the the driveshaft that is connected to the axle that supports the smaller tires. In doing so, the drive shafts are maintained it in a generally horizontal orientation. This requires additional componentry to achieve the stepped configuration which unnecessarily adds to the expense and complexity of the driveline. In order to avoid this problem other arrangements have utilized a driveline which extends from the output portion of the engine to the axle at a rather steep angle. The angularity must be accommodated by U-joints that are specifically designed to operate in this condition. This type of U-joint is also extremely expensive and, even though it is specifically designed to accommodate this specific condition has also been known to be the source of frequent driveline failures.
The present invention is directed to overcoming one or more of the problems as set forth above.